Cold is not what kills roses in Hawaii. Where people garden, it never freezes, so the roses that hold up are the ones that shrug off heat, steady rain, salt wind and fungus. Knock Out, New Dawn, Hansa and Therese Bugnet clear that bar. Many of the hybrid teas on the garden center shelf do not. Planting basics are covered in growing roses in Hawaii. Choosing the right plant is the harder part.
Which roses survive a Hawaii winter
The USDA Plant Hardiness Zone Map puts Hawaii in zones 9a to 13a. That system rests on a single number, the average annual extreme minimum temperature, and the range covers the entire state, so your own yard sits somewhere inside it. The cold end of the range belongs to high ground. The warm end belongs to the coastal lowlands.
Does it ever freeze where roses grow in Hawaii?
Not in the places people live. NOAA’s NCEI climate normals for the Honolulu airport station record zero days a year at or below 32°F, and the freeze percentiles can’t even be computed because the freezes never happen. Frost shows up only on the summits of Mauna Kea, Mauna Loa and Haleakala, far above any garden. That means there is no frost calendar to plan around. Rainfall, elevation and whether you sit on the windward or leeward side of your island do the sorting instead.
Cold-hardy types clear the bar with room to spare. Rugosa roses and the Explorer series, bred in Canada for winters that would flatten most garden plants, never meet anything close to their limit here. Hybrid teas are the type that needs help in cold country, where gardeners mound soil over the graft union to get them through a freeze. Hawaii’s range starts at 9a, so none of that applies. Every common type clears the cold test.
What threatens roses here if cold does not?
Heat in the lowlands, humidity that rarely lets up, wind, salt spray near the coast, and the lack of any real dormant season. A rose that never rests keeps producing soft new growth, and soft new growth is exactly what fungus likes. Winter is also the wetter season across much of the state, so the weather that tests a rose from November through March is rain, not ice. The wet-season routine is laid out in Protecting Roses Through a Hawaii Winter.
Elevation shifts the picture. On cooler upland slopes, the cold-bred rugosas make more sense because nights cool off and the plants get a break. In hot lowland yards, modern disease-resistant shrubs and the old China roses do better. Pick the type for your slope and exposure, then pick the name.
Named roses that hold up here
A handful of cultivars keep turning up in warm, wet, disease-prone gardens. Each earns its place for a different reason, and each can be bought at a nursery or ordered from a rose grower.
Which shrub roses hold up in Hawaii?
Knock Out is the default answer, and it deserves the reputation. It was bred for disease resistance and repeat bloom, and it keeps flowering through heat and humidity that flatten fussier roses. It holds its leaves better than most roses through months of wet weather, though constant rain can still bring some leaf spotting. It asks for sun, a pruning when it gets leggy, and little else. For a first rose in a lowland yard, it is the safest purchase.
Hansa and Therese Bugnet are rugosas, and they come at the problem from the opposite direction. Hansa is a Dutch-bred shrub with fragrant, double, magenta-purple flowers, and Therese Bugnet is a pale pink hybrid rugosa bred in Alberta by Georges Bugnet. Both have thick, wrinkled, leathery leaves that stand up to wind and salt spray better than the glossy foliage of a hybrid tea. They are bred for cold, so freezing is never a worry. Heat is the test. Give the rugosas your coolest, breeziest spot, whether that is an upland garden or the windward edge of a lot, and expect them to behave best where nights cool off.
Which climbers and old garden roses hold up?
New Dawn is a vigorous, pale pink climber that repeats its bloom, tolerates some shade, and has a long record of shrugging off disease in warm climates. It will cover a fence or an arbor quickly, which is a mixed blessing in a place where everything grows fast. Plan for a sturdy support and an annual trim.
Old Blush and Mutabilis, two China roses, suit gardeners who want flowers nearly all year. China roses evolved in warm, humid regions and bloom in waves rather than in one spring flush. Mutabilis opens buff-yellow and ages through pink to crimson on the same shrub. William Baffin, an Explorer climber, is the pick for a taller, tougher plant at higher, cooler elevations.
Sold here, but not for this zone
Garden centers in Hawaii order from the same national catalogs as stores in Ohio or Oregon. A rose can sit on the shelf in perfect health with a cheerful tag and still be a poor bet for a humid island yard. The tag is written for a national audience, so it won’t tell you.
- Hybrid teas and grandifloras, bred for cool-summer cut-flower gardens and prone to leaf spot where the air stays damp
- English-style roses with heavy, many-petaled flowers that ball up and rot in persistent rain
- Rugosas planted in hot, low, humid yards, where they sulk compared with their performance higher up
- Gift-shop miniature roses, grown in greenhouses and often exhausted by the time they reach a home garden
These are not doomed. A hybrid tea in a sunny, breezy spot with good airflow can bloom well for years. But it will drop leaves to black spot in a wet stretch, and it needs a plan. See Rose Diseases in Hawaii: What the Climate Here Actually Brings for what that looks like in practice. Commit to a regular spray and pruning routine before you buy one, because a plant bought on impulse and left alone will be a bare stick within a season or two.
The winter kits sold on some shelves, with foam cones and mounding bags, are for climates that freeze. They have no job here. Skip them and spend the money on a better plant.
What to check on the label before buying
Start with the grade. Bareroot and bagged roses are sold as Grade 1, 1½ or 2, and Grade 1 is the top: the thickest canes, the most of them, and the best odds of fast establishment. A cheaper, lower-grade plant is a slower plant. Potted roses are often sold without a grade, so judge them by cane thickness and color. Plump green canes beat shriveled brown ones.
Next, find out whether the rose is grafted or own-root. A grafted rose has a named variety joined to a different root system. An own-root rose is the variety all the way down. In a freezing climate the difference is a big one, because a grafted rose that dies back to the ground can lose the variety and sprout from the rootstock instead. The colder the winter, the more that matters, which is why own-root plants are prized in cold country. Hawaii’s gardens don’t freeze, so this risk is small here. Own-root still helps, because a rose cut hard back or damaged by wind comes back true to its name. Check the tag for “own root” or “grafted” and ask if it isn’t printed.
Checking this against your own county
Hawaii packs a wide span of conditions into a small area. A rose that thrives in a dry leeward yard can melt in a rain-soaked windward valley, and a spot a few hundred feet higher may be cooler than a mile away at the coast. The University of Hawaii CTAHR Cooperative Extension keeps offices and agents across the islands who know the local rainfall, soils and common problems. Call or visit the extension office on your island before you buy, and bring your elevation and which side of the island you’re on.
Common questions
These come up most often at nursery counters and extension desks.
Do roses need winter protection in Hawaii?
No. Frost occurs only on the high volcanic summits, never where people garden. The wet season is the real winter test, so good drainage and airflow matter more than any wrap or mound.
Is Knock Out the best rose to buy in Hawaii?
It is the safest first choice for a lowland yard because it keeps blooming through heat and humidity with little fuss. It isn’t the only good one. New Dawn, Old Blush and Mutabilis also hold up well, and the rugosas suit cooler, breezier sites.
Can I grow a hybrid tea in Hawaii?
Yes, with work. Give it full sun, wide spacing for airflow and a steady disease-control routine, and accept that it may drop leaves in long wet spells. Expect more upkeep than from a Knock Out.
Does windward or leeward matter for choosing a rose?
A great deal. Windward sides get more rain and humidity, which favors fungal problems and the disease-resistant types. Leeward sides are drier and sunnier, and a wider range of roses can work there if they get water.